1. Field of the Invention
THIS INVENTION relates to coupling devices and particularly a coupling for connecting a vacuum line to a body such as an autoclave having an internal chamber to be evacuated.
2. Description of the Prior Art
A coupling of this kind conventionally comprises a cylindrical body which is threadedly engaged upon the wall of the autoclave about an aperture therein, using PTFE tape or the like to provide a seal and to prevent leakage past the thread. Such a coupling requires frequent replacement in view of the high temperatures experienced in the operation of such equipment. This is carried out by unscrewing the coupling from the autoclave wall and replacing it with renewed tape or other sealing medium.
Notwithstanding frequent replacement, there is a continuous risk of leakage past the thread.